1. Field of the Invention
The present invention is related to a wireless local area network (WLAN) and more particularly, to a WLAN with connected wireless communication devices.
2. Background Description
The Institute of Electrical and Electronics Engineers (IEEE) wireless protocol designated 802.11b is an Ethernet local area network (LAN) variant. Ethernet technology has shown an amazing ability to adapt to new requirements, evolving from a simple 10 Mbps bus to gigabit full-duplex switched networks and to wireless LANs. Ethernet is well understood and there is a wealth of experience with cost reduction and integration of Ethernet devices. Some current Ethernet interface cards (10BaseT) retail at less than $10. 802.11b wireless LAN (WLAN) card technology is subject to the same economy of scale and prices have fallen to less than 30% of their relatively recent original prices. Given its track record, Ethernet is a low-risk, extensible technology suited, for example, to address challenges in wide-area mobility.
Consequently, WLAN technology has been characterized as a disruptive technology. In other words, WLAN technology may change paradigms and lead to unexpected and unpredictable market developments. Past examples of disruptive technologies are the telephone, the personal computer (PC) and the Internet. Today, WLANs are becoming ubiquitous offering cheap solutions for both home and office networks. Currently however, there are three major limitations on WLAN technology: speed, range and security.
The 802.11b standard supports speeds of up to 11 Mbs. However, 802.11a and 802.11g are promising to deliver much higher speeds. Although range is limited, typically, to about fifty meters (50 m) outdoors, tests have demonstrated a range capability of up to 20 miles using directional antennas. Work is continuing to expand the coverage of the wireless base stations. Wired Equivalent Privacy (WEP) for wireless networks has proven far less secure than was intended. The security limitations of WEP are now well understood and work is on-going to enhance these protocols to improve the security of wireless interfaces.
The IEEE 802.1Q virtual LAN (VLAN) protocol defines interoperability operation of VLAN bridges. 802.1Q permits the definition, operation and administration of VLAN topologies within a bridged LAN infrastructure, such that LANs of all types may be connected together by Media Access Control (MAC) bridges.
Heretofore, these Ethernet LAN variants have been relatively rigidly architected. Once attached or connected, a device could communicate freely with other attached devices. If after sending a request, however, the connection is lost prior to receiving a response, the response was lost. Once reconnected, whether to the same or a different port and, even prior to arrival of the response, the response was lost and the request had to be sent anew. This is still the case for state of the art VLANs and even for devices wirelessly connected to such a VLAN. So, if a wireless device that is connected to a VLAN through an access point leaves the access point's reception area, it must re-establish communications. This is true even if it never leaves the overall LAN reception area, i.e., the area covered by all connected access points, and even if it remains in the reception area of another connected access point.
Beyond the wireless LAN coverage area, the wireless device must find some other way to connect, either wired (for example with a modem) or wirelessly. Other wireless technologies, especially wireless cell phone technologies, provide a more or less suitable connection (albeit an expensive one) when an access point isn't readily available. As wireless communications technology advances towards next generation higher speed communications, the performance of this type of alternate connection may become acceptable, but cost is still expected to be a barrier to exclusive use. So, wireless LAN connections will remain preferable.
Furthermore, manually switching between cellular (or other wireless communications technology) and a lower cost wireless LAN connection is very disruptive. Thus, someone that expects to be moving between areas where a wireless LAN connection may or may not be available, must either accept connection disruptions or pay a premium to connect to another wireless service to maintain a constant connection.
Thus, there is a need for a wireless LAN wherein a wirelessly connected device can roam freely and still maintain a connection to the wireless network, and that can maintain a connection even outside the range of the Wireless LAN using a second network